A single vPro machine can be accessed via WebUI, but does not appear in DNS. Its name does not get resolved in NSLookup?
NSLookup does not use the standard client resolver routines but uses similar routines of its own. If true, this means a valid name-IP record could be cached on the client and being used by IE to resolve the name even though NSLookup fails to resolve the name and there is no DNS record.
To determine this, do the following: